A variety of transposable genetic elements have been identified. A well studied insect transposable element, P, O'Brochta et al., mobility of P elements in drosopholids and nondrosopholids, NPAS 85,6052-6056 (1988) has, despite substantial study, failed to provide a mechanism for affecting recombination outside of drosophila. Other transposable elements, including hobo isolated from T. melanogaster, Ac from Zea mays and Tam 3 from antirrhinum majus have all been identified as having common elements. Calvi et al., Cell 66, p. 465-471 (1991). These are constituent members of a family of transposase members which are identified by terminal inverted repeat sequences sandwiching a sequence encoding a transposase protein in a single open reading frame (ORF), the protein generally consisting of three identifiable domains. This family is identified as a family of transposable elements or hAT elements.
The preparation of transgenic, recombinant insect cell lines and insects continues to be an object of substantial commercial interest. The preparation of biological control agents capable of passing a dominant lethal genotype to a wild population, or infertile mating competitors, is currently effected through the use of blind chemical or irradiation mutagens. Tools for preparing effective recombinant individuals selected for a specific genotype would greatly improve these modalities.
Additionally, genetic analysis, protein assays and the like are all capable of making use of such tools. Additionally, insect cell lines are currently used for the expression of foreign proteins. The proteins expressed in these insect cell systems can have a variety of uses. Currently, most insect cell expressions systems are transient (as opposed to continuous) and based on baculovirus infection. Continuous expression systems are advantageous.
Further, altering genotypes by the introduction of an exogenous gene is widely applicable technology. Gene therapy relies on just such a process. Transgenic technology is also being developed for animals for the purposes of improved livestock, poultry or aquaculture production. Thus, the provision of an effective system for achieving recombination of exogenous material into a host for expression of the same continues to be an object of those of skill in the art.